The seat for vehicles having a configuration where the surface of a pad (urethane pad) formed of foam molded urethane is covered with the surface member (trim cover) has been commonly used. If the surface member is not fixed to the urethane pad, the surface member is displaced relative to the urethane pad when an occupant seated on the seat for vehicles moves thereon. This may lead to decrease in seating comfort for the seated occupant.
For the purpose of prevention of the displacement, Patent Literature 1 discloses a method of integrally molding the urethane pad and the surface member by forming the surface member substantially in a bag shape, followed by injecting a resin foam raw material in the surface member and foaming the material.